scholarly journals The mental workload of harvester operators working in steep terrain conditions

Silva Fennica ◽  
2020 ◽  
Vol 54 (3) ◽  
Author(s):  
Grzegorz Szewczyk ◽  
Raffaele Spinelli ◽  
Natascia Magagnotti ◽  
Paweł Tylek ◽  
Janusz Sowa ◽  
...  
Keyword(s):  
Mental Workload ◽  
Work Conditions ◽  
Slope Gradient ◽  
Activity Cycles ◽  
The Mean ◽  
Gradient Measurements ◽  
Steep Terrain ◽  
Difficult Terrain ◽  
Steep Slopes ◽  
Saccade Duration

The use of modern multi-functional forestry machines has already been associated with central nervous system fatigue induced by high mental workload. As these machines are being used under increasingly difficult terrain conditions, further knowledge is required on the expected aggravation of operators’ mental workload, so that suitable work/rest schedules can be developed. Within such a context, the aim of this study was to gauge aggravations of mental workload derived from increasing slope gradient. Measurements of eye activity were obtained from a representative harvester operator working in corridors with the following mean inclinations: 9%, 23% and 47%. The duration, frequency and trajectory of eye movements were used to determine the harvester operator’s mental workload, on the assumption that worsening work conditions would be reflected by increased eyeball activity. The number of fixations during the performance of all tasks increased with the increasing slope gradient. Similarly, fixation duration increased with slope gradient. The mean duration of saccades when working on a 23% slope was 5% shorter compared to work under a 9% gradient. A further significant shortening of saccade duration (~22%) occurred when working on a 47% slope. The good match between eye activity cycles and work cycles, visible especially on steep slopes, indicates that mental workload is related to work conditions. Overall, operating a forest harvester on steep slopes results in a greatly increased mental workload and calls for suitable rest schedules.

scholarly journals Personnel's Health Surveillance at Work: Effect of Age, Body Mass Index, and Shift Work on Mental Workload and Work Ability Index

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Shahram Safari ◽  
Jafar Akbari ◽  
Meghdad Kazemi ◽  
Mohammad Amin Mououdi ◽  
Behzad Mahaki
Keyword(s):  
Body Mass Index ◽  
Body Mass ◽  
Shift Work ◽  
Work Ability ◽  
Mental Workload ◽  
Work Conditions ◽  
Developed Countries ◽  
Work Ability Index ◽  
Ability Index ◽  
The Mean

Introduction.Two great changes in developed countries are taking place: populations are ageing and becoming increasingly overweight. Combination of these factors with shift work is a risk factor for work ability and mental workload that are dynamic processes which change greatly throughout an individual's work life. The aim of this study was to investigate mental workload and work ability in textile workers and to identify factors which affect work ability and mental workload.Methods.This cross-sectional study was carried out among 194 male workers in textile industry. Employees based on their job group and work conditions have been divided into 6 categories. They completed work ability index and mental workload questionnaires during three work shifts. Body mass index (BMI) and demographic details were recorded.Results.All of the participants rated their work ability as moderate with high mental workload. The mean WAI and mental workload in age group were significant. The mean BMI was 25.5 kg/m2(standard deviation 4.1) and the mean age was 40.22 years. There was a statistically significant correlation between work ability index and shift work.Conclusions.Unlike the previous study, a decrease point in WAI started in early age that may be due to life-style work and another psychological factor; on the other hand, NASA-TLX revealed high score in six subscales that can be another reason for low WAI.

scholarly journals Perception of the Harvester Operator’s Working Environment in Windthrow Stands

Forests ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 168
Author(s):  
Grzegorz Szewczyk ◽  
Raffaele Spinelli ◽  
Natascia Magagnotti ◽  
Bartosz Mitka ◽  
Paweł Tylek ◽  
...  
Keyword(s):  
Mental Workload ◽  
Work Conditions ◽  
Control Area ◽  
Working Environment ◽  
Movement Variability ◽  
Tracking Method ◽  
The Mean ◽  
And Control ◽  
Mean Time ◽  
Successive Operation

The aim of the study was to determine the mental workload of a harvester operator when working in late thinning and in windthrown stands of the same type and age, using eye movement patterns as an indicator. Eyeball movement variability was analysed using the eye tracking method. The mean duration of eyesight fixations in windthrown stands was shorter than in the control undamaged stands by about 20% (444 ms and 534 ms, respectively). The mean time of eyesight movements (saccades) in the windthrown stands was shorter than in the control undamaged stands by approx. 15%. The largest differences between the duration of saccades in the windthrown and control stands were observed between the cutting of trees and cutting logs off their root plates: the saccades were longer by about 20% when working in the control stands (49 ms) as compared to the windthrown stands (43 ms). Large differences in the duration of saccades between the windthrown area (42 ms) and the control area (47 ms) were also found when travelling between successive operation sites. In both types of stands, the shortest saccades were observed during processing: 39 ms. Summary durations of saccades observed during the processing of successive trees occurred in sequences showing repeated periods of variable eyeball activity, where longer saccades were followed by shorter ones. Documented more variability of eyesight activities of the harvester operator performing the operations of processing and moving is new standard of eye balls activities for the more taxing work conditions presented by windthrown stands.

GAMBARAN BEBAN KERJA MENTAL PADA DOSEN FAKULTAS X UNIVERSITAS X

2019 ◽  
Vol 2 (3) ◽  
Author(s):  
Kartiani Dewi ◽  
Suryani S ◽  
Ahmad Yamin
Keyword(s):  
Community Service ◽  
Mental Workload ◽  
Sampling Technique ◽  
Mean Value ◽  
Descriptive Statistics ◽  
Large Contribution ◽  
Mean Dimension ◽  
The Mean ◽  
Quantitative Descriptive ◽  
University Lecturers

Lecturers are responsible for implementing the three main responsibilities in university (Tridharma Perguruan Tinggi) with 12 credits to 16 credits each semester. However, many lecturers feel that the workload is very excessive. The purpose of this study was to describe the mental workload of lecturers at the Faculty of X Padjadjaran University. The method of this research was quantitative descriptive by using a total sampling technique involving 43 lecturers. Data collection used NASA-TLX instruments. Data were analysed using descriptive statistics. The results of the study showed that overall the mental workload of the Faculty of X Padjadjaran University lecturers was included in the high category both in education and teaching assignments (74.4%), research assignments (76.7%), and community service assignments (74.4%). ) Effort dimensions have the highest mean value that is equal to 51.8, while the dimensions that have the lowest mean are Perfomance dimension, namely 9.4, where the greater the mean dimension shows the large contribution in the mental workload felt by the lecturer. The conclusions, this study show that most lecturers have a high mental workload. It is suggested that the lecturers need to have balance numbers of tasks according to their abilities, balance the time working with recreation, and meet the needs of rest. The results of this study need to be followed up by examining methods or efforts that can reduce the lecturers' mental workload.

scholarly journals Application of digital image processing in slope surface runoff velocity analysis under simulated rainfall conditions

2017 ◽  
Vol 49 (4) ◽  
pp. 1304-1312
Author(s):  
Tiexiong Gong ◽  
Yuanjun Zhu
Keyword(s):  
Image Processing ◽  
Surface Runoff ◽  
Lateral Diffusion ◽  
Ease Of Use ◽  
Velocity Analysis ◽  
Slope Gradient ◽  
Tracer Method ◽  
Dye Tracer ◽  
The Mean ◽  
High Runoff

Abstract To have accurate runoff velocity, there is need to improve dye tracer method for estimating surface runoff velocity. This can enhance the calculations of relevant hydrologic parameters that will lead to a better understanding of hydrological processes and soil erosion. In this study, an integrated dye tracer and image processing method (IPV) and dye tracer method (AOV), respectively, were used to estimate runoff velocity under three slope gradients (5°, 10°, and 15°) and three slope positions (up-slope, mid-slope, and down-slope). The results showed more variation in runoff velocity under IPV than AOV. Both IPV and AOV were positively correlated with slope gradient. IPV values were close to AOV ones for slope gradients ≤5°, but were significantly different for slope gradients ≥10°. The mean AOV value was 10.6% higher than that of IPV. Regression analysis showed that compared with AOV, IPV overestimated and underestimated runoff under low and high runoff velocity conditions, respectively. The use of image processing in IPV was advantageous because of its ease of use with fewer artificial errors and its suitability for lateral diffusion of runoff. Irrespectively, additional studies are needed to verify and/or improve further the use of this method in runoff velocity analysis.

Time-Based Modeling of Human Performance

2005 ◽  
Vol 49 (12) ◽  
pp. 1200-1204 ◽  
Author(s):  
Esa M. Rantanen ◽  
Brian R. Levinthal
Keyword(s):  
Human Performance ◽  
Mental Workload ◽  
Probabilistic Approach ◽  
The Other ◽  
Performance Variables ◽  
The Mean ◽  
And Performance ◽  
Methods Of Measurement

This paper presents a probabilistic approach to modeling human performance. Instead of focusing on mean performance, the effects of taskload on the distributions of performance variables are examined. From such data, probabilities of given levels of performance can be derived and methods of measurement that expand the analyses beyond those of the mean developed. Results from two experiments, one abstract, the other realistic, are presented in terms of timely performance on required tasks. As taskload increased, the participants were less likely to act on the experimental tasks at an earliest opportunity than under low taskload, resulting in increase of “too late” errors. Measurement of taskload and performance in temporal terms also allowed for bracketing and making inferences about mental workload, which is not directly measurable.

Pipeline Route Assessment at River Crossings and in Steep Terrain: Geophysical, Hydrologic and Geotechnical Characterization

2002 ◽  
Author(s):  
Gilein J. Steensma ◽  
Mark A. Kappelhoff ◽  
Duncan A. McInnis ◽  
Eric Gilson
Keyword(s):  
Seismic Refraction ◽  
Geophysical Data ◽  
River Channels ◽  
Refraction Tomography ◽  
Geological Conditions ◽  
Geophysical Surveys ◽  
The Face ◽  
Steep Terrain ◽  
Difficult Terrain ◽  
Lateral Variations

Pipeline river crossings and sections of pipeline routes where steep terrain requires directionally drilled borings have the highest chance of being successfully designed and constructed if subsurface geological conditions are understood. In this paper we present results of geophysical surveys conducted to characterize the subsurface at two pipeline river crossings and at a site where steep topography would likely require directional boring below the face of a steep hillside. The objective is to help assess and minimize the risk in engineering design in difficult terrain by analyzing subsurface geology from geophysical data and vertical geotechnical borings, and evaluating the dynamic behavior of the river itself through hydrologic analysis. Risk factors can be assigned on the basis of lithology and environmental considerations relating to the level of potential impact in different parts of the crossing. The laterally heterogeneous nature of river channels, consisting of stacked paleochannels and floodplains could require a significant number of vertical geotechnical borings for adequate characterization of the entire crossing. We find that a combination of electrical resistivity tomography (ERT), seismic refraction tomography (SRT) and ground penetrating radar (GPR) data can efficiently provide us with an understanding of electrical and mechanical properties from which lateral variations and depth extent of lithology along the proposed boring can be inferred. Confirmatory vertical geotechnical borings allow us to verify our interpretation at two locations. Geophysical data are used to laterally extrapolate the lithologic interpretation and define, in conjunction with surface water hydrologic considerations, the minimum depth of directionally drilled borings and optimum locations of ingress/egress points. The investment in a geological assessment study to understand subsurface conditions prior to beginning horizontal boring operations is essential to mitigate risk and ultimately may save money. In the case of steep terrain, geophysical data can provide valuable information on the vertical and lateral variations in subsurface properties in areas where it would be impossible to safely drill vertical borings. Our last case history is an example of the geological information that can be efficiently inferred from geophysical surveys conducted in steep terrain.

scholarly journals Assessing Harvested Sites in a Forested Boreal Mountain Catchment through Global Forest Watch

2019 ◽  
Vol 11 (5) ◽  
pp. 543 ◽  
Author(s):  
Fernando Rossi ◽  
Johannes Breidenbach ◽  
Stefano Puliti ◽  
Rasmus Astrup ◽  
Bruce Talbot
Keyword(s):  
Forest Cover ◽  
Risk Mitigation ◽  
Landsat Imagery ◽  
Aerial Images ◽  
Catchment Management ◽  
South Central ◽  
Cable Yarding ◽  
The Mean ◽  
Steep Terrain ◽  
Forest Cover Loss

Global Forest Watch (GFW) provides a global map of annual forest cover loss (FCL) produced from Landsat imagery, offering a potentially powerful tool for monitoring changes in forest cover. In managed forests, FCL primarily provides information on commercial harvesting. A semi-autonomous method for providing data on the location and attributes of harvested sites at a landscape level was developed which could significantly improve the basis for catchment management, including risk mitigation. FCL in combination with aerial images was used for detecting and characterising harvested sites in a 1607 km2 mountainous boreal forest catchment in south-central Norway. Firstly, the forest cover loss map was enhanced (FCLE) by removing small isolated forest cover loss patches that had a high probability of representing commission errors. The FCLE map was then used to locate and assess sites representing annual harvesting activity over a 17-year period. Despite an overall accuracy of >98%, a kappa of 0.66 suggested only a moderate quality for detecting harvested sites. While errors of commission were negligible, errors of omission were more considerable and at least partially attributed to the presence of residual seed trees on the site after harvesting. The systematic analysis of harvested sites against aerial images showed a detection rate of 94%, but the area of the individual harvested site was underestimated by 29% on average. None of the site attributes tested, including slope, area, altitude, or site shape index, had any effect on the accuracy of the area estimate. The annual harvest estimate was 0.6% (standard error 12%) of the productive forest area. On average, 96% of the harvest was carried out on flat to moderately steep terrain (<40% slope), 3% on steep terrain (40% to 60% slope), and 1% on very steep terrain (>60% slope). The mean area of FCLE within each slope category was 1.7 ha, 0.9 ha, and 0.5 ha, respectively. The mean FCLE area increased from 1.0 ha to 3.2 ha on flat to moderate terrain over the studied period, while the frequency of harvesting increased from 249 to 495 sites per year. On the steep terrain, 35% of the harvesting was done with cable yarding, and 62% with harvester-forwarder systems. On the very steep terrain (>60% slope), 88% of the area was harvested using cable yarding technology while harvesters and forwarders were used on 12% of the area. Overall, FCL proved to be a useful dataset for the purpose of assessing harvesting activity under the given conditions.

scholarly journals Workload assessment for mental arithmetic tasks using the task-evoked pupillary response

2015 ◽  
Author(s):  
Gerhard Marquart ◽  
Joost de Winter
Keyword(s):  
Mental Arithmetic ◽  
Pupil Diameter ◽  
Mental Workload ◽  
Self Report ◽  
Blink Rate ◽  
Eye Tracker ◽  
Practical Applications ◽  
The Mean ◽  
Nasa Tlx ◽  
Diameter Change

Pupillometry is a promising method for assessing mental workload and could be helpful in the optimization of systems that involve human-computer interaction. The present study focuses on replicating the studies by Ahern (1978) and Klingner (2010), which found that for three levels of difficulty of mental multiplications, the more difficult multiplications yielded larger dilations of the pupil. Using a remote eye tracker, our research expands upon these two previous studies by statistically testing for each 1.5 s interval of the calculation period (1) the mean absolute pupil diameter (MPD), (2) the mean pupil diameter change (MPDC) with respect to the pupil diameter during the pre-stimulus accommodation period, and (3) the mean pupil diameter change rate (MPDCR). An additional novelty of our research is that we compared the pupil diameter measure with a self-report measure of workload, the NASA Task Load Index (NASA-TLX), and with the mean blink rate (MBR). The results showed that the findings of Ahern and Klingner were replicated, and that the MPD and MPDC discriminated just as well between the lowest and highest difficulty levels as did the NASA-TLX. The MBR, on the other hand, did not interpretably differentiate between the difficulty levels. Moderate to strong correlations were found between the MPDC and the proportion of incorrect responses, indicating that the MPDC was higher for participants with a poorer performance. For practical applications, validity could be improved by combining pupillometry with other physiological techniques.

scholarly journals CHARACTERISTICS OF FLOW IN RUN-UP OF PERIODIC WAVES

1976 ◽  
Vol 1 (15) ◽  
pp. 44 ◽  
Author(s):  
Ary Roos ◽  
Jurjen A. Battjes
Keyword(s):  
Slope Angle ◽  
Water Layer ◽  
Periodic Waves ◽  
Wave Steepness ◽  
Slope Gradient ◽  
Characteristic Parameters ◽  
Similarity Parameter ◽  
The Mean ◽  
Run Up ◽  
Particle Velocities

An experimental study is presented of some characteristic parameters of the flow in the up-rush and down-rush of periodic waves breaking on a plane, smooth slope. The water layer thickness has been measured as a function of time at four locations above still water level. Discharges and particle velocities have been calculated. The results have been made nondimensional on the basis of Hunt's formula for the run-up height. They appear to be either independent of the wave steepness H/L and slope gradient tan Ct or to be a function of a single similarity parameter £ - tana / yH/L only. An hypothesis is stated concerning a relation between the mean rate of overtopping of a dike by waves, and the run-up which would occur under the same circumstances on an uninterrupted slope. On the basis of this hypothesis the overtopping volume per wave can be normalized so as to make it independent of slope angle and wave steepness. A comparison of the result with measurements from other sources indicates a rough agreement.

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